Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

On Fri, Dec 16, 2016 at 11:41:36AM -0200, Eduardo Habkost wrote: > On Fri, Dec 16, 2016 at 11:03:33AM +0100, Paolo Bonzini wrote: > > I'd like to make a few cleanups and add more documentation: > > > > Looks good to me. > > Reviewed-by: Eduardo Habkost +1

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

On Fri, Dec 16, 2016 at 11:03:33AM +0100, Paolo Bonzini wrote: > I'd like to make a few cleanups and add more documentation: > Looks good to me. Reviewed-by: Eduardo Habkost > diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c > index eacc9dc..f767ea9 100644 > ---

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

I'd like to make a few cleanups and add more documentation: diff --git a/hw/i386/kvm/clock.c b/hw/i386/kvm/clock.c index eacc9dc..f767ea9 100644 --- a/hw/i386/kvm/clock.c +++ b/hw/i386/kvm/clock.c @@ -37,7 +37,7 @@ typedef struct KVMClockState { uint64_t clock; bool clock_valid; -

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

> > > > > On Mon, Dec 12, 2016 at 02:36:55AM -0500, Pankaj Gupta wrote: > > > > > > Hello Marcelo, > > > > Hi Pankaj, > > > > > > Check for KVM_CAP_ADJUST_CLOCK capability KVM_CLOCK_TSC_STABLE, which > > > > indicates that KVM_GET_CLOCK returns a value as seen by the guest at > > > > that

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

On Mon, Dec 12, 2016 at 05:44:52PM -0200, Marcelo Tosatti wrote: > On Mon, Dec 12, 2016 at 04:01:05PM -0200, Eduardo Habkost wrote: > > On Sat, Dec 10, 2016 at 03:21:50PM -0200, Marcelo Tosatti wrote: > > [...] > > > static void kvmclock_realize(DeviceState *dev, Error **errp) > > > { > > >

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

On Mon, Dec 12, 2016 at 04:01:05PM -0200, Eduardo Habkost wrote: > On Sat, Dec 10, 2016 at 03:21:50PM -0200, Marcelo Tosatti wrote: > [...] > > static void kvmclock_realize(DeviceState *dev, Error **errp) > > { > > KVMClockState *s = KVM_CLOCK(dev); > > > > +if

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

On Sat, Dec 10, 2016 at 03:21:50PM -0200, Marcelo Tosatti wrote: [...] > static void kvmclock_realize(DeviceState *dev, Error **errp) > { > KVMClockState *s = KVM_CLOCK(dev); > > +if (kvm_has_adjust_clock_stable()) { > +s->clock_is_reliable = true; > +} > + This seems

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

> > On Mon, Dec 12, 2016 at 02:36:55AM -0500, Pankaj Gupta wrote: > > > > Hello Marcelo, > > Hi Pankaj, > > > > Check for KVM_CAP_ADJUST_CLOCK capability KVM_CLOCK_TSC_STABLE, which > > > indicates that KVM_GET_CLOCK returns a value as seen by the guest at > > > that moment. > > > > > > For

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

On Mon, Dec 12, 2016 at 02:36:55AM -0500, Pankaj Gupta wrote: > > Hello Marcelo, Hi Pankaj, > > Check for KVM_CAP_ADJUST_CLOCK capability KVM_CLOCK_TSC_STABLE, which > > indicates that KVM_GET_CLOCK returns a value as seen by the guest at > > that moment. > > > > For new machine types, use

Re: [Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

Hello Marcelo, > > Check for KVM_CAP_ADJUST_CLOCK capability KVM_CLOCK_TSC_STABLE, which > indicates that KVM_GET_CLOCK returns a value as seen by the guest at > that moment. > > For new machine types, use this value rather than reading > from guest memory. > > This reduces kvmclock

[Qemu-devel] [qemu patch V4 2/2] kvmclock: reduce kvmclock difference on migration

Check for KVM_CAP_ADJUST_CLOCK capability KVM_CLOCK_TSC_STABLE, which indicates that KVM_GET_CLOCK returns a value as seen by the guest at that moment. For new machine types, use this value rather than reading from guest memory. This reduces kvmclock difference on migration from 5s to 0.1s (when